1. Field of the Invention
The present invention relates to a machine tool, and more particularly to a machine tool having a coaxial driving device to suitably drive or rotate the tool members without generating shocks or vibrations.
2. Description of the Prior Art
Various kinds of typical machine tools comprise a cutting tool or various machining tool members, and a motor driving mechanism coupled to the tool members, to rotate or to drive the tool members, in order to cut or to machine various objects or work pieces.
For example. U.S. Pat. No. 2,941,446 to Senglet, U.S. Pat. No. 3,538,778 to Harris, and U.S. Pat. No. 4,018,113 to Blazemin et al. disclose three of the typical machine tools each also comprising a cutting tool or a machining tool member that is required to be coupled to, and rotated or driven by motor driving mechanisms.
Normally, the cutting tools or the machining tool members include an axle offset from the driving spindles of the motor driving mechanisms, and coupled to the driving spindles of the motor driving mechanisms with various coupling devices or members or mechanisms, to allow the tool members to be rotated or driven by the motor driving mechanisms.
However, due to the separation or the offset of the tool members from the driving spindles of the motor driving mechanisms, a driving torque may be formed between the tool members and the driving spindles of the motor driving mechanisms, such that shocks or vibrations may have a great chance to be generated by the tool members, and such that the work pieces may not be precisely cut or machined by the tool members. In addition, the work pieces may have a good chance to be damaged by the tool members, and the working life of the tool members may thus be greatly decreased.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional machine tools.